A W-18 engine using similar construction to the 12WE was next introduced. With a 130 mm (5.118″) bore, 180 mm (7.087″) stroke, 43.005 l (2,624.3 in³) displacement it was rated 600 hp at 1,860 rpm and weighed 1,848 lb. As with the 12WE the cylinders, built up in pairs, each had four interchangeable overhead valves operated by rocker arms and push rods from camshafts in the Vees. Articulated connecting rods were used and the link rods had tubular shanks. These engines were either direct-drive or used Farman bevel-planetary reduction gears with standard 2:1, 1.83:1, 1.67:1 and 1.5:1 ratios. Six carburetors, three on each side, fed three cylinders each.
The 18WD, a more refined version of the earlier W-18, was rated 700 hp at 1,850 rpm and produced 820 hp at 2,100 rpm. It weighed 1,716 lb and consumed 0.495 lb/hp/hr. It was equipped with magneto and battery ignition.
All Aero 